Carpal tunnel syndrome (CTS) is the most common malady affecting the hand. The basic underlying cause is pressure on the median nerve as it passes through the carpal tunnel at the wrist. Once pain begins, the condition gradually worsens and may result in permanent nerve damage. It is common for CTS to occur in both hands.

Anatomy

The carpal tunnel is formed by eight carpal bones in a U-shape on the posterior (back) aspect of the wrist and the transverse carpal ligament (also referred to as the flexor retinaculum) bridging across the carpal bones on the anterior (front) aspect of the wrist (Figure 1)

Through the 'tunnel' formed by the bones and ligament pass the tendons that allow the fingers to flex and the median nerve

The median nerve is responsible for conducting sensations such as pain from the thumb and first two fingers, and the adjacent palm of the hand. The nerve also controls some muscles that move the thumb

The cause of median nerve compression is varied. It effects women more than men and is most common in the fifth and sixth decades of life

Some of the specific causes are:

Various diseases such as rheumatoid arthritis, amyloidosis, and hypothyroidism (low thyroid), diabetes mellitus, and alcoholism

Repetitive movements of the wrist such a typing or computer use

Fractures involving the bones of the wrist

Use of air tools

Masses in the carpal tunnel such as a ganglion cyst

Fluid retention as may occur with pregnancy

History and Exam

A typical patient with a carpal tunnel syndrome complains of numbness or tingling in the fingers and hands

These sensations most typically occur in the thumb and first two fingers and the adjacent palm of the hand (Figure 2)

This may be described as pins and needles or heaviness

These sensations usually occur at night causing the individual to awaken and shake his hands

The pain may also occur with repetitive movements of the hand such as typing or sewing and while driving or using a computer 'mouse'

Sometimes the pain may effect the entire hand and even radiate up the arm to the shoulder and thus be confused with a ruptured cervical disk

Examination may reveal a wrist deformity or swelling

There may be a decrease in sensation over the thumb and first two fingers and at the base of these digits

Occasionally there is weakness of the thumb

About two-thirds of individuals with CTS will have an electrical sensation in the hand when the doctor taps over the median nerve at the wrist (Tinel's sign)

Another test that is more specific for the CTS is reproduction of the symptoms on flexion of the wrist with the forearm held vertically (Phalen's sign)

Tests

Sometimes X-rays of the wrist may be of help, especially if there is a history of injury

Electomyography (EMG) including nerve conduction velocity studies of the median nerve usually confirm the diagnosis

The most sensitive and earliest abnormality is a prolongation of sensory nerve impulses of the median nerve across the wrist

Later in the disease process, EMG may reveal a loss of nerve function in the thumb muscles innervated by the median nerve

Non-operative Therapy

Many cases of CTS are self-limiting

This is especially true of minor cases and those related to a disease that has been successfully treated such as low thyroid treated with thyroid medication

CTS developing during pregnancy frequently disappears after delivery

Modifying work habits may decrease or eliminate the pain such as minimizing repetitive hand movements by periodically resting the hands

Splints that reduce the amount of wrist flexion and extension. The splints should be used at night as well as during the day for work

Medication that reduces swelling and inflammation. Steroid medication (cortisone) may be injected into the carpal tunnel or non-steroidal anti-inflammatory drugs such as Ibuprofen may be given by mouth

The Procedure

Surgery is indicated when there is progressive wasting of the muscles in the hand innervated by the median nerve or the pain is unable to be relieved by conservative means

When both hands are involved, the most affected hand is usually operated first

There are several surgical procedures for releasing or decompressing the carpal tunnel

The classical operation is as follows:

An incision is made in the hand and wrist. (Figure 3)

The incision is carried down to the transverse carpal ligament (flexor retinaculum), which is cut throughout its length (Figure 4)

The wound is then sutured

Retinaculotomy is a technique that minimizes the incision in the hand

A small incision is made centered over the wrist or in the hand (Animation)

The transverse carpal ligament is opened at the wrist or in the hand following which a special instrument is used to cut the ligament in the hand

This instrument has a blunt foot plate with a sharp blade oriented perpendicular to the foot plate. The foot plate is slipped over the median nerve to protect it as the blade cuts the ligament The instrument may also come with a built in light source

Endoscopic carpal tunnel release is similar to retinaculotomy

Two small incisions, one at the wrist and the other in the palm of the hand, are used to insert a tubular instrument called an obturator

The obturator is passed from the incision in the wrist to the incision in the hand

The obturator is then removed leaving a slotted cannula under the ligament

The endoscope is then inserted from the hand towards the wrist along the course of the slotted cannula. The endoscope carries a light source, a fiber optic connection to a television camera and a working port

Under visualization, a hook shaped knife is used to cut the transverse carpal ligament

Reflex sympathetic dystrophy causing burning pain along with changes in the bone and skin. The skin is initially shiny red and later becomes cool and blue. The cause is unknown

After Surgery

After surgery the hand and forearm are usually wrapped in a bandage designed to minimize post-operative bleeding and swelling

To reduce swelling, it is best to keep the hand elevated at night on two pillows and in a sling for the first five days

After removal of the sutures, the hand may return to normal function

The patient should not try to use the hand for heavy lifting or any activity that may strike the hand for 4-6 weeks after surgery

Occasionally physical or occupational therapy may be required for range of motion exercises, control of swelling, scar management, progressive strengthening activities and job modification to prevent recurrence

Cubital Tunnel Release(Release of ulnar nerve entrapment at the elbow)

Cubital tunnel syndrome is also called Ulnar Neuritis. Entrapment of the ulnar nerve is the second most common nerve entrapment after the median nerve in the carpal tunnel and may or may not be due to trauma.

Anatomy

The ulnar nerve runs in the upper arm along medial (inside) aspect of the brachial artery. In the middle third of the upper arm the nerve passes through the medial intermuscular septum, a fibrous band between the muscles on the back and front of the upper arm, towards the medial aspect of the elbow

The ulnar nerve then passes behind the medial aspect of the elbow into the cubital tunnel (Figure 5)

The cubital tunnel starts at the groove in the back of the medial epicondyle of the humerus. The epicondyle is the lower flared out end of the humerus (see Long Bone Fractures)

In the cubital tunnel, the ulnar nerve lies on the medial collateral ligaments of the elbow joint and is covered by the arcuate ligament passing from the lower end of the humerus to the ulna

On exit from the cubital tunnel the nerve passes into the flexor carpi ulnaris muscle where it gives off some branches and then passes further down the forearm to the hand

In the ulnar groove, there is little tissue overlying the ulnar nerve

The cubital tunnel is narrowed when the elbow is flexed and distorts the ulnar nerve

The ulnar nerve may also be distorted at the intermuscular septum and where it passes into the flexor carpi ulnaris muscle

The most prominent symptom is a sharp ache or pain in the elbow that passes down the medial aspect of the forearm towards the ring and little fingers

Pain and paresthesias (tingling, numbness) in the distribution noted above occurring when the patient sleeps with the elbow flexed

Paresthesias may occur with the elbow flexed and light pressure over the cubital tunnel

Tapping over the ulnar nerve in the cubital tunnel may cause an electric shock feeling that travels to the little and ring fingers

Numbness and paresthesias may occur in the little and ring fingers

There may be a decrease in sensation to touch and pain in the ring and little fingers and adjacent palm of the hand (Figure 2)

There may be weakness and atrophy of the small muscles of the hand with weakness of the grip and in spreading the fingers against resistance

With severe injury there may be an ulnar claw hand deformity in which the last two fingers are extended at the joint at the base of the fingers and the fingers flexed at the finger joints (Figure 6)

Figure 6 - Claw hand due to injury of the ulnar nerve.

Tests

Plain X-ray of the elbow to look for fracture, arthritis, bony spurs or abnormal range of motion at the elbow

Electromyography (EMG) of the muscles innervated by ulnar nerve

Nerve conduction studies of the ulnar nerve looking for a slowing of nerve impulse conduction across the cubital tunnel

Non-surgical therapy

Elbow pads for daily use

Elbow splints at night

Non-steroidal anti-inflammatory drugs such as ibuprofen

Avoidance of repetitive flexion and extension of the elbow, particularly against resistance

Surgical Procedures

The procedure is usually carried out as an outpatient in an ambulatory care setting

General anesthesia or local anesthesia supplemented with neuroleptic analgesia is used (see Anesthesia)

Simple decompression of the ulnar nerve

The incision is about 4 - 5 inches long centered at the elbow. (Figure 7A) The incision may be in back of the elbow over the course of the ulnar nerve or the incision may be curvilinear starting over the intermuscular above the elbow, passing anterior to the elbow and finishing over the flexor carpi ulnaris muscle (Figure 7B)

The ulnar nerve is released by cutting the arcuate ligament (Figure 7C)

The nerve is followed upward and released at the intermuscular septum

The nerve is followed below the elbow into the flexor carpi ulnaris and released from any constricting bands (Figure 7C)

The incision is then closed with sutures

Decompression and anterior subcutaneous transposition of the ulnar nerve

The curvilinear incision is used and the nerve released as described above

The nerve is placed in front of the elbow

A tunnel is then formed in the fatty tissue beneath the skin with a few absorbable sutures and the incision closed with sutures (Figure 7D)

Medial epicondylectomy

The simple decompression of the nerve is carried out

The medial epicondyle in front of the nerve is removed with a chisel

Soft tissues are sutured over the raw bone surface and the incision closed with sutures